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The Single UNIX &reg; Specification, Version 2<br>
Copyright &copy; 1997 The Open Group

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<h4><a name = "tag_000_008_333">&nbsp;</a>NAME</h4><blockquote>
sem_unlink - remove a named semaphore
(<b>REALTIME</b>)
</blockquote><h4><a name = "tag_000_008_334">&nbsp;</a>SYNOPSIS</h4><blockquote>
<pre><code>

#include &lt;<a href="semaphore.h.html">semaphore.h</a>&gt;

int sem_unlink(const char *<i>name</i>);
</code>
</pre>
</blockquote><h4><a name = "tag_000_008_335">&nbsp;</a>DESCRIPTION</h4><blockquote>
The
<i>sem_unlink()</i>
function removes the semaphore named by the string
<i>name</i>.
If the semaphore named by
<i>name</i>
is currently referenced by other processes, then
<i>sem_unlink()</i>
has no effect on the state of the semaphore.  If one or more processes
have the semaphore open when
<i>sem_unlink()</i>
is called, destruction of the semaphore is postponed until
all references to the semaphore have been destroyed by calls to
<i><a href="sem_close.html">sem_close()</a></i>,
<i><a href="_exit.html">_exit()</a></i>,
or
<i>exec</i>.
Calls to
<i><a href="sem_open.html">sem_open()</a></i>
to re-create or re-connect to the semaphore refer to a new semaphore
after 
<i>sem_unlink()</i>
is called.  The
<i>sem_unlink()</i>
call does not block until all references have been destroyed; it
returns immediately.
</blockquote><h4><a name = "tag_000_008_336">&nbsp;</a>RETURN VALUE</h4><blockquote>
Upon successful completion, the function returns a value of 0.
Otherwise, the semaphore is not changed and the
function returns a value of -1 and sets
<i>errno</i>
to indicate the error.
</blockquote><h4><a name = "tag_000_008_337">&nbsp;</a>ERRORS</h4><blockquote>
The 
<i>sem_unlink()</i>
function will fail if:
<dl compact>

<dt>[EACCES]<dd>
Permission is denied to unlink the named semaphore.

<dt>[ENAMETOOLONG]<dd>

The length of the
<i>name</i>
string exceeds {NAME_MAX} while {POSIX_NO_TRUNC} is in effect.

<dt>[ENOENT]<dd>
The named semaphore does not exist.

<dt>[ENOSYS]<dd>
The function
<i>sem_unlink()</i>
is not supported by this implementation.

</dl>
</blockquote><h4><a name = "tag_000_008_338">&nbsp;</a>EXAMPLES</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_008_339">&nbsp;</a>APPLICATION USAGE</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_008_340">&nbsp;</a>FUTURE DIRECTIONS</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_008_341">&nbsp;</a>SEE ALSO</h4><blockquote>
<i><a href="semctl.html">semctl()</a></i>,
<i><a href="semget.html">semget()</a></i>,
<i><a href="semop.html">semop()</a></i>,
<i><a href="sem_close.html">sem_close()</a></i>,
<i><a href="sem_open.html">sem_open()</a></i>,
<i><a href="semaphore.h.html">&lt;semaphore.h&gt;</a></i>.
</blockquote><h4>DERIVATION</h4><blockquote>
Derived from the POSIX Realtime Extension (1003.1b-1993/1003.1i-1995)
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UNIX &reg; is a registered Trademark of The Open Group.<br>
Copyright &copy; 1997 The Open Group
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